Can a temporal lobar bleed be caused by a road traffic accident, especially in patients with a history of hypertension or anticoagulant (anti-clotting) medication use?

Can Temporal Lobar Bleed Be Due to a Road Traffic Accident?

Yes, temporal lobar bleeds can absolutely be caused by road traffic accidents, and trauma is a well-established mechanism for lobar intracerebral hemorrhage, particularly in patients with underlying risk factors such as hypertension or anticoagulant use. 1

Traumatic Mechanism of Lobar Hemorrhage

Lobar hemorrhages occur in approximately 42% of traumatic brain injuries from road traffic accidents, making them a common consequence of blunt head trauma. 2 The temporal lobe is particularly vulnerable due to:

• Acceleration-deceleration forces during motor vehicle collisions that cause shearing of cortical vessels 3
• Direct impact trauma to the temporal region from lateral collisions or ejection 2
• Contrecoup injury patterns where the brain impacts the skull opposite the site of direct trauma 1

Risk Factors That Increase Vulnerability

Hypertension

Hypertension is the leading cause of lobar hematomas even in traumatic settings, as chronic hypertensive changes weaken vessel walls making them more susceptible to rupture with trauma. 4, 5 In one series, arterial hypertension was identified as the predominant underlying cause in lobar hemorrhages, with the parietotemporal region being the most common location 4.

Anticoagulation

Patients on anticoagulants have a 3.9% risk of significant intracranial injury after head trauma versus 1.5% in non-anticoagulated patients, representing a nearly 3-fold increased risk. 6 Specific considerations include:

• Warfarin users have a 10.2% incidence of intracranial hemorrhage after trauma 6, 7
• Novel oral anticoagulants (NOACs) like apixaban carry a lower but still elevated risk of 2.6% 6, 7
• Antiplatelet agents including clopidogrel carry similar bleeding risks and should not be considered safer 6
• Anticoagulated patients have a 3-fold increased risk of hemorrhage expansion (26% versus 9% in non-anticoagulated patients) 6

Cerebral Amyloid Angiopathy (CAA)

In elderly patients, underlying cerebral amyloid angiopathy makes vessels particularly vulnerable to even minor trauma, with lobar hemorrhages occurring after relatively mild head injuries. 3 The replacement of contractile arterial components by amyloid renders cerebral vessels more susceptible to acceleration-deceleration forces, independent of trauma severity 3.

Clinical Presentation and Diagnosis

Immediate non-contrast head CT is mandatory for any patient with head trauma, especially those on anticoagulation, regardless of symptom severity or mechanism of injury. 6 Common clinical findings in temporal lobar hemorrhages include:

• Hemiparesis and hemisensory deficits (most common) 4
• Visual field defects due to involvement of optic radiations 4
• Seizures in 23% of patients with lobar hemorrhages 4
• Coma is infrequent at onset compared to deep hemorrhages 4

Management Priorities

Immediate Actions for Anticoagulated Patients

If CT shows intracranial hemorrhage in an anticoagulated patient:

• Immediately discontinue the anticoagulant and consult neurosurgery 6
• For warfarin: Administer 4-factor prothrombin complex concentrate (4F-PCC) plus 5mg IV vitamin K to achieve INR <1.5 6
• For factor Xa inhibitors: Use andexanet alfa as specific reversal agent; if unavailable, use prothrombin complex concentrate 6
• Obtain repeat head CT within 24 hours due to the 3-fold increased risk of hemorrhage expansion 6

Surgical Considerations

Hematoma size on CT correlates directly with outcome and surgical decision-making: 4

• Small hematomas: Medical management is appropriate with good outcomes 4
• Medium and large hematomas: Mortality rates of 14% and 60% respectively, with surgical evacuation potentially beneficial when consciousness progressively deteriorates or CT shows prominent midline shift 4

Common Pitfalls to Avoid

• Failing to obtain initial CT imaging in anticoagulated patients after any head trauma, even with minor mechanisms like ground-level falls 6, 7
• Assuming lobar hemorrhages are always "spontaneous" without considering recent trauma history, particularly in elderly patients with CAA 3
• Discontinuing anticoagulation without considering the indication, as thromboembolic risk may outweigh the small risk of delayed hemorrhage 6, 7
• Premature discharge without adequate observation for high-risk patients (age >65, anticoagulant use, GCS <15) 7

Prognosis

Overall mortality for traumatic extra-axial hematomas is 18.7%, with most deaths occurring within the first month. 2 For lobar hemorrhages specifically, mortality was 32% in one series, with outcomes strongly correlated to initial hematoma size 4.